Assertion   :       Urinary bladder and ureters are lined by transitional epithelium.

Reason      :       Ureters carry the urine to urinary bladder where it is stored temporarily.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion   :       In vertebrates, the liver is also referred as an accessory excretory organ.

Reason      :       Liver helps kidneys in the secretion of urine.
1.  Both A & R are true and the R is the correct explanation of the A.
2.  Both A & R are true but the R is not the correct explanation of the A.
3.  A is true statement but R is false.
4.  Both A and R are false statements.

Assertion   :       Sharks are said to be ammonotelic animals.

Reason      :       Sharks can retain considerable amounts of ammonia in their blood.

Assertion   :       Aquatic mammals like whales and seals are said to be ureotelic animals.

Reason      :       It is because of the fact that their main nitrogenous waste product is urea.

Assertion   :       Death ensues if waste products are not removed from the body.

Reason      :       Excretory system removes the nitrogenous waste products from the body.

Assertion   :       Camel can go without water for long periods.

Reason      :       Camels stores water in the pouches of their rumen and fat in their hump.

Assertion   :       Renal threshold of glucose is said to be 180 mg per 100 ml.

Reason      :       Glucose starts appearing in the urine when its blood level exceed 180 mg per 100 ml of blood.

Assertion   :       Earthworms excrete both ammonia and urea.

Reason      :       Excretion in earthworm depends on the environment.

Assertion   :       If human urine is allowed to stand for some time, it smells strongly of ammonia.

Reason      :       Main constituent of human urine is Ammonia.

Assertion   :       Birds can considerably reduce water loss in the urine.

Reason      :       Birds store urine along with faeces in the cloaca.